Mainspring and winder

[admitch]

How do you know which mainspring to order on a pocket watch? As an example, assume I have a 12s 1923 Elgin movement. The serial number being 26947394 (1923 303 12s 03n3p 7j). I have seen a procedure to measure old spring width/depth/etc, but seems to leave some things out – and you cannot order in advance of repair.

Another question – is there a less expensive mainspring winder for pocket watches?

[tokei]

Hi admitch,
Since I notice a bit of a quiet spell on the board let me give you my 1,5 cents here.
I’ve been doing some repairing myself and most PW’s have been Elgin.
What I do is go to http://elginwatches.org/scans/tech_doc/1915_MC/m_index.html
Once you know the class you just page down to the Spring section and look it up.
The least expensive mainspring winder I’ve come across are my fingers
I start from the barrel hook end of the spring carefully pushing it in the barrel.
Don’t force anything and no sharp bending just help it in.
I did order a used K&D set from Uncle Larry’s but haven’t really used it yet.
Well hope that helped.
Greetings,
Cornelio

[admitch]

Thanks Cornelio,

The Elgin document you referenced was Outstanding. It was a parts catalog of 1915. The mainsprings were listed but I was confused with the reference to steel, thick going, and thin going barrels. I did not know what a “going” barrel was?

There are several good items on this website, I wish we had material catalogs for all manufacturers and years.
The 1915 catalog did cover most of the Elgin movements which were used later as well – great reference.

[tokei]

Your welcome,
I agree this is a great site for detailed info on Elgin.
As far as I understand (better Google it) going barrel is the usual configuration where you wind the mainspring via the arbor and the barrel drives the movement. there are other styles like motor barrel which is the reverse. you wind via the barrel and drive the movement with the arbor. This is safer for the delicate gears if the mainspring should break. Steel barrel should be obvious, most i’ve seen were brass. Thick or thin is a bit more tricky, should be dimension info somewhere.
Anyway glad it helped I use this site all the time.

Cornelio

[Author]

Posts